Interesting conversation.
Yes, there are different reasons and different ways to play the game. I enjoy creating my own fluff and story line, and have got gritched at by those who like to play the official story lines. I enjoyed painting up my highly irregular all female Imperial Guard, Demon and Chaos marine armies (originally one force until the rules changed). Some people like the originality, others don't.
My first army was Eldar. Lots of people recommend marine armies as first armies, but marines can be played brute force head on. Can't do that so much with Eldar. You have to use speed, maneuverability and carefully plan which of your units will engage which enemy unit. Thus I see opponents playing a much more brute force straight ahead game than I prefer. This is fine as an individual choice, less fine when the games and scenarios are slanted towards making the brute force sort of play inevitable.
I have encountered a store with a dominant clique of shooting players, where the players who chose assault armies gave up the game in disgust. I have encountered stores with dominant cliques of rhino rushers. Starting out as the Eldar player, where I can't do what is fashionable and popular at any given time, I've always been the joker, the one who designs a force to stop the fashionable popular trend rather than being part of the dominant crowd subtly or not so subtly trying to shift the culture of the store to favor their armies, their style of play. To me, playing the role of the joker seems like an honorable role, but it doesn't always make one popular. Cliques of veteran players leaning in a particular direction are not healthy for the community.
Years ago, I came up with a fluff army, the Cult of Khaine. It was basically 8 squads of Eldar aspect warriors, one from each temple, plus an Avatar. GW recently reinvented the concept as an Apocalypse data sheet. It's the only losing army I've ever played that got driven from the store with cries of cheese. Every single unit had a different special rule, unusual weapon or crazy ability. It drove opposition not used to Eldar nuts. It was also very fragile. It had no focus. I couldn't win with it. People complained loudly and bitterly as they pounded me into the dirt. Fluff, GW's or original, is sometimes interesting, but it doesn't always make everyone happy.
Anyway, not every player is pleased to game against every other player. There are painters, there are story tellers, and there are competitors. I'd like to think I'm one of many who does some of each. I've learned there are some I can't compete against, and some who paint much better or much worse than I. Some have obvious themes and stories, while others just want to deploy and start rolling dice.
I don't know that the community gains when some refuse to play against the unpainted army, when others play to win with a vengeance, using every trick in the book against rank beginners, when others work themselves into an angry frenzy upon seeing a converted model they don't like, or deliver long angry lectures upon seeing a perfectly legal force that isn't built according to their idea of the fluff.
If a given opponent isn't a lot of fun, avoid that opponent, but don't try to tell him he is playing the game wrong. Don't try to ruin anyone's fun.
New players, sure, they will be trying hard to win. They generally have to use every trick they've got to be competitive against anyone except each other. Are there veteran fluffy players who are really scared? (Insert silly school yard level taunting noises here.) In time, the new people will become old people, and appreciate other aspects of the game. The game always needs new blood. The last thing the veterans should do is close ranks and exclude. I've seen this done. The stores are now closed.